<template>
	<view>
		<view class="search-box">
			<my-search @click="gotoSearch"></my-search>
		</view>
		 
		<view class="scroll-view-container">
			<!-- 左侧滑动区 -->
			<scroll-view class="left-scroll-view" scroll-y="true" :style="{height: wh + 'px'}">
				<view :class="['left-scroll-view-item',i ===active? 'active':'' ]" v-for="(item,i) in cateList" :key="i" @click="activeChanged(i)">{{item.cat_name}}</view>
				
			</scroll-view>
			<!-- 右侧滑动区 -->
			<scroll-view scroll-y="true"  :style="{height: wh + 'px'}" :scroll-top="scrollTop">
				<view class="cate-lv2"  v-for="(item2,i2) in cateLevel2" :key="i2">
					<!-- 二级分类标题 -->
					<view class="cate-lv2-title">
					/	{{item2.cat_name}} /
					</view>
					<!-- 动态渲染三级列表区域 -->
					<view class="cate-lv3-list">
						<view class="cate-lv3-item" v-for="(item3,i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
								<image :src="item3.cat_icon" mode=""></image>
								<text>{{item3.cat_name}}</text>
							</view>
						</view>
					</view>
					
			
			</scroll-view>
		</view>
	</view>
</template>

<script>
		import badgeMix from '@/mixins/tabbar-badge.js'
	export default {
		mixins:[badgeMix],
		data() {
			return {
				// 当前设备可用高度
				wh:0,
				// 默认第一项选中
				active:0,
				// 分类列表数据
				cateList:[],
				// 二级分类列表
				cateLevel2:[],
				// 滚动条距顶部的距离
				scrollTop:0
			};
		},
		onLoad() {
			// 获取当前设备可用高度
			const sysinfo = uni.getSystemInfoSync()
			// console.log(sysinfo);
			this.wh = sysinfo.windowHeight - 50
			this.getCateList()
		},
		methods:{
			async getCateList() {
				const {data:res} = await uni.$http.get('/api/public/v1/categories')
				if(res.meta.status !== 200) return uni.$showMsg()
				this.cateList = res.message
				// 二级分类列表
				this.cateLevel2 = res.message[0].children
			},
			// 点击左侧的索引的处理函数
			activeChanged(i){
				this.active = i
				// 二级分类列表重新赋值
				this.cateLevel2 = this.cateList[i].children
				//控制scrolltop的距离，不能赋予相同的值，否则没效果，可以赋值为1，视觉体验上是没有区别的
				this.scrollTop =  this.scrollTop ? 0 : 1
			},
			// 跳转到商品列表页面的函数
			gotoGoodsList(item3) {
				// 点击三级分类的图片 就会跳转到对应的列表页面
				uni.navigateTo({
					url:'/subpkg/goods_list/goods_list?cid='+item3.cat_id
				})
			},
			gotoSearch() {
				// 跳转到分包的搜索页面
				uni.navigateTo({
					url:'/subpkg/search/search'
				})			
			}
		}
	}
</script>

<style lang="scss">
.scroll-view-container {
	display: flex;
	.left-scroll-view {
		width: 120px;
		.left-scroll-view-item {
			background-color: #F7F7F7;
			line-height: 60px;
			text-align: center;
			font-size: 12px;
			&.active {
				background-color: #fff;
				position: relative;
				&::before {
					content: '';
					display: block;
					width: 3px;
					height: 30px;
					background-color: #C00000;
					position: absolute;
					top: 50%;
					left: 0;
					transform: translateY(-50%);
				}
			}
		}
	}
}
.cate-lv2-title {
	font-size: 12px;
	font-weight: bold;
	padding: 15px 0;
	text-align: center;
}
.cate-lv3-list {
	display: flex;
	flex-wrap: wrap;
	.cate-lv3-item {
		width: 33.33%;
		margin-bottom: 10px;
		display: flex;
		flex-direction: column;
		align-items: center;
		image {
				width: 60px;
				height: 60px;
		}
		text {
			text-align: center;
			font-size: 12px;	
		}
	}
	
}
.search-box {
	position: sticky;
	top: 0;
	z-index: 999;
}
</style>
